As per the given chemical formula- Na2CO3.10H2O, one mole of the chemical compound contains 13 moles of oxygen atoms. Hence
Number of moles of oxygen atoms in one mole of Na2CO3.10H2O = 13
number of moles of oxygen atoms in 0.2 moles of Na2CO3.10H2O = 13 X 0.2 = 2.6
Now, one mole of a substance contains 6.022 X 10^23 particles of the substance. Thus
number of atoms of oxygen in one mole of oxygen atom = 6.022 X 10^23
number of moles of oxygen atoms in 2.6 moles of oxygen atoms = 2.6 X 6.022 X 10^23 = 15.657 X 10^23
= 1.566 X 10^24
Thus, there are 1.566 X 10^24 atoms of oxygen in 0.2 moles of Na2CO3.10H2O.
4.7
Answer:
The SI units for measuring the velocity of the car: meters per second
(m/s)
The Sl units for measuring the acceleration of the car: meters per second squared (m/s^2)
The SI units for measuring force: Newton (N)
The SI units for measuring mass: kilograms (kg)
Explanation:
Système international (SI) or International System of Units consist of a list of unit measurement that mostly used by scientist. The scientist from a different country might use different unit that makes them have to convert the result of each other. The usage of the same unit measurement will help the scientist to read that publication easier, make it easier to share and discuss any topic. The unit used is metric since the decimal system also makes the conversion of a unit easier.
Answer:


Explanation:
Hello,
Based on the given undergoing chemical reaction is is rewritten below:

By stoichiometry we find the minimum mass of H2SO4 (in g) as shown below:

Moreover, mass of H2 gas (in g) would be produced by the complete reaction of the aluminum block turns out:

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Answer:
A. 8.4
Explanation:
[OH⁻] = 2.6 × 10⁻⁶ Take the negative log of each side
-log[OH⁻] = pOH = 5.59 Apply the pH/pOH relation
pH + pOH = 14.00 Insert the value of pOH
pH + 5.59 = 14.00 Subtract 5.59 from each side
pH = 14.00 -5.59 = 8.41